Inlet construction for vacuum vessels

ABSTRACT

THE INVENTION IS AN IMPROVEMENT OVER AN INLET CONSTRUCTION SHOWN IN AN EARLIER APPLICATION. THE EARLIER CONSTRUCTION INCLUDES A VERTICALLY MOVABLE TUBE MOUNTED IN THE INLET OPENING OF A VACUUM VESSEL, A SPRING URGING THE TUBE UPWARDLY INTO CONTACT WITH A TEEMING VESSEL, AND A BELLOWS SURROUNDING THE TUBE TO RETAIN THE VACUUM. THE IMPROVEMENT IS AN ARRANGEMENT TO BALANCE THE DOWNWARD PULL OF THE VACUUM ON THE TUBE, WHEREBY THE FULL FORCE OF THE SPRING URGES THE TUBE UPWARDLY.

Feb. 16, 1971 F. GALLUCCI l-.TAL 3,563,938

INLET CONSTRUCTION FOR VACUUM VESSELS Filed May 16. 1969 [/VI/EN TO!? F RANC/S GALLUCC/ W, v //W/ Attorney United States Patent O INLET CONSTRUCTION FOR VACUUM VESSELS Francis Gallucci, North Huntingdon Township, Westmoreland, County, Pa., assiguor to United States Steel Corporation, a corporation of Delaware Filed May 16, 1969, Ser. No. 825,255 Int. Cl. C21c 7/10 U.S. Cl. 266-34 ABSTRACT OF THE DISCLOSURE The invention is an improvement over an inlet constuction shown in an earlier application. The earlier construction includes a vertically movable tube mounted in the inlet opening of a vacuum vessel, a spring urging the tube upwardly into contact with a teeming vessel, and a bellows surrounding the tube to retain the vacuum. The improvement is an arrangement to balance the downward pull of the vacuum on the tube, whereby the full force of the spring urges the tube upwardly.

This invention relates to an improved inlet construc tion through which liquds can be introduced to a vessel which is under vacuum.

Although my invention is not thus limited, my inlet Construction is particularly useful as applied to a vacuumdegassing vessel which receives molten steel from a bottom-pour teeming vessel. The latter vessel has an outlet opening in its bottom wall and a closure tor controlling flow of metal through this opening. To maintain the vacuum in the receiving vessel, it is necessary that there be an enclosed passage between the two vessels. One arrangement which can be used to provide an enclosed passage includes a refractory tube mounted for vertical movement in the inlet opening of the receiving vessel, and a spring which urges the tube upwardly into engagement with the teeming vessel. This arrangement is shown in detail and claimed in Shapland application Ser. No. 808,841 filed Mar. 20, 1969, of common ownership. I have observed this arrangement gives rise to a problem that the vacuum in the receiving vessel tends to draw the tube downwardly against the action of the spring and may cause the tube to lose contact with the teeming vessel and thus break the vacuum.

An object of my invention is to provide an improved inlet Construction which utilizes the foregoing arrangement, but overcomes the tendency of the vacuum to draw the tube away from the teeming vessel.

A more specific object is to provide an inlet Construction of the foregoing type wherein the forces which the vacuum eXerts on the tube are balanced, enabling the spring to hold the tube against the teeming vessel with a uniform pressure.

In the drawing:

FIG. 1 is a tragmentary top plan view of a receiving vessel equipped with my improved inlet construction; and

FIG. 2 is a vertical section on a larger scale on line II-II of FIG. 1, showing also a portion of a teeming vessel.

FIG. 2 shows portions of a teeming vessel 10 and receiving vessel 12, both of which are refractory lined for containing molten metal. suitable mechansm, not shown, is connected to the receiving vessel for maintaining it under vacuum. The bottom of the teeming vessel has an outlet opening 13 and carries a nozzle 14 fixed to its underside aligned with the opening. A sliding gate closure member 15 is mounted beneath the nozzle and has an opening 16 which can be aligned with the nozzle opening to permit teeming. The gate can be supported and operated in any desired manner; hence I have not shown the 3 'Claims ICC supporting and Operating mechanism. The top wall of the receiving vessel 12 has a metal cover plate 17 and an inlet opening 18 through the cover plate and refractory lining.

As shown and claimed in the aforementioned Shapland application, a refractory tube 21 is mounted in the opening 18. The tube is aXially movable and it has a metal casing 22 over the portion which extends upwardly of the vessel wall. Lower and upper annular collars 23 and 24 are fixed to the cover plate 17 and to the upper end ot the casing 22 respectively. A compression spring 25 encircles tube 21 and bears at its ends against the two collars and thus urges the tube upwardly with respect to the vessel. The confronting faces of the collars have annular grooves which receive lower and upper followers 28 and 29 respectively. An expansible metal bellows 30 is joined at its ends to the two followers and encircles tube 21 within spring 25. The bellows provides a seal around the outside of tube 21 and prevents loss of vacuum within vessel 12. A cylindrical shield 31 rests on the cover plate 17 and surrounds the spring 25, bellows 30 and tube 21. The shield has an inlet 32 for admitting cooling air.

Collar 24 carries a rectangular plate 33 fixed to its upper face. In the Construction illustrated, the plate carres angle iron guides 34 for the sliding gate closure member 15. A plurality of hold-downs 35 are pivoted to the top of the cover plate 17 and are received in notches 36 n the side edges of plate 33. The upper end of each holddown carries a pair of spaced collars 37 and 38, nuts 39 holding the upper collar, and a compression spring 40 between said collars. The lower collar bears against the upper face of plate 33. The central portion of each holddown includes a turnbuckle 41 for adjusting the force of ts spring 40'.

In accordance with my invention, I mount a plurality of auxiliary expansible metal bellows 44 on the cover plate 17 at locations spaced from the inlet opening '18. I show four bellows 44, two on each side of plate 33 (FIG. l), but the number and arrangement may vary. 'Each bellows 44 is smaller than bellows 30 and its interior communicates with the inside of the receiving vessel 12 via a Conduit indicate& diagrammatically at 45. The upper faces of the bellows 44 carrying respective upstanding plungers 46. The cover plate 17 also carries upstanding brackets 47 corresponding in number to the bellows 44 and located between the plate 33 and the respective bellows. Rocker arms 48 are pivoted to the upper ends of brackets 44 and to the upper ends of plungers 46. One end of each rocker arm bears against the underside of plate 33. Each bellows 44 is housed in a respective cylindrical shield 49, which has an inlet 50 for admitting cooling air.

In operation, the teeming vessel 10 is lowered to a position in which its outlet opening 13 is aligned with the inlet opening 18 of the receiving vessel 12. Gate 15 lies between the two guides 34 and abuts the top of tube 21. The compression spring 25 forces the upper end of the tube into close engagement with the gate. Thereafter the gate can be opened to permit molten metal or other liquid to flow from vessel 10 to vessel 12. The vacuum in vessel 12 acts on all the bellows 30 and 44 to contract them. Contraction of bellows 30 tends to draw tube 21 downwardly out of contact with the receiving vessel, but contraction of bellows 44 acts'through the rocker arm 48 to push upwardly on plate 33. In this manner the upward and downward forces which the vacuum eXerts on the tube are in balance, and the spring 25 holds the tube firmly in contact with the teeming vessel.

From the foregoing description it is seen that my invention affords a simple effective means for overcomin g the problem that the vacuum in the receiving vessel tends to draw the tube out of contact with the teeming vessel in the Construction shown in the Shapland application. Thus the nventon renders the Construction more positive in its action and assures that the vacuum is maintained, and that the full force of the spring urges the tube upwardly.

I claim:

1. The combination, with a receiving vessel adapted to be maintained under vacuum and having an nlet Opening in its top wall, of an nlet Construction comprsing a tube nounted in said opening for axial movement and having a portion extending upwardly of the top Wall of the vessel, spring means urgng said tube upwardly, an expansible bellows surrounding said tube to provide a seal to retan the vacuum in the vessel but having a tendency to pull said tube downwardly against the action of said spring means, and means acting on said tube to balance said tendency, whereby the full force of said spring means u'ges said tube upwardly.

2. A combination as defined in claim 1 whe'ein the means actng on said tube includes a pluralty of auxilary expansible bellows mounted on said vessel and communicating with the interior thereof, and means connecting said auxiliary bellows with said tube to push the tube up wardly.

3. A combination as defined in claim 2 in which said last-named means includes respective rocker arms pivoted to said vessel and to said auxiliary bllows.

References Cited UNITED STATES PATENTS 2,959,024 11/1960 Eckert et al. 141-311X 3,384,362 5/1968 Phlbrick, Jr. 266-34 JAMES M. MEISTER, Primary Examiner U.S. Cl. X.R. 

